By harnessing the power of
Iridium, DENSO is suddenly able to shrink the surface area of the center
electrode - the critical component of a spark plug. Unlike a typical platinum
plug that has a 1.1mm diameter center electrode, DENSO Iridium Power plugs have
the world's smallest center electrode measuring 0.4mm in diameter. This means
that the voltage requirements are decreased while firing performance is greatly
improved.

U-Groove Technology

Our patented U-Groove design changed the
industry standard in the mid 1970s by providing a better design that virtually
eliminates erratic starts caused by poor fuel mixture. The U-Groove results in
less flame dissipation making the spread of the flame nucleus easier and
therefore yielding greater firing energy. It gives the flame a groove to grow
in, thereby creating a larger flame front for a complete combustion.

On
a conventional plug, the flat electrode design crushes the spark, and the
overall volume of the flash front is smaller.

The conventional method to
improve firing was to increase the spark gap. This has a negative effect on the
spark. With a U-Groove firing can be greatly improved without increasing the
spark gap.

To help improve ignitability DENSO minimized the portion
of the ground electrode that comes in contact with the flame nucleus. Because
the area of the ground electrode where the tapered cut comes into contact with
the flame nucleus is small, the heat lost to the electrode is lessened and
firing performance improves dramatically. The surface area and weight of the
ground electrode tip is reduced along with the load in terms of heat and
vibrations. This means the spark plug can cope with heavier driving conditions.